LSA question (Cam Guys)
Thread Starter
Joined: Jan 2005
Posts: 1,475
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From: Munfordville KY
LSA question (Cam Guys) I'm getting ready to order a custom cam, and the one that I got a sheet for was set up on a 112lsa. If I changed it to a 111lsa would it screw with valve timing or anything? What effects would it hurt? I know it should bump up DCR just a tad. What else would it do? Thanks
11 Second Club
Joined: Dec 2005
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From: Midland, GA
I am certainly not a "cam guy"; but I do know that the valve events will change with a resultant increase in overlap and DCR. Whether the effects will be good or bad will depend upon the other specs of the cam in question and how it fits into the total package for your car.
Thread Starter
Joined: Jan 2005
Posts: 1,475
Likes: 1
From: Munfordville KY
Originally Posted by eLTwerker
It will change the valve events. It will give more overlap and slightly more DCR. Plug your cam #s into J-Rod's VE calculator and change the LSA and see how it changes your valve events.
Matt,
When you specified your preferred street manners, you asked for a cam with a light chop, not a heavy lope. Here's what you got:
Camshaft Valve Events: 0.006 0.05 0.2
Intake Duration - ID 280 230 154
Exhaust Duration - ED 279 230 151
Lobe Center Angle - LSA 112 112 112
Intake Centerline - ICL 108 108 108
Intake Valve opens - IVO 32 7 -31 BTDC (- indicates ATDC)
Intake Valve closes - IVC 68 43 5 ABDC
Exhaust Valve Opens - EVO 75.5 51 11.5 BBDC
Exhaust Valve Closes - EVC 23.5 -1 -40.5 ATDC (- indicates BTDC)
Exhaust Centerline - ECL 116 116 116
Overlap 55.5 6 -71.5 degrees
DCR = 7.90:1
Change it to a 111LSA +4, this is what you get:
Camshaft Valve Events: 0.006 0.05 0.2
Intake Duration - ID 280 230 154
Exhaust Duration - ED 279 230 151
Lobe Center Angle - LSA 111 111 111
Intake Centerline - ICL 107 107 107
Intake Valve opens - IVO 33 8 -30 BTDC (- indicates ATDC)
Intake Valve closes - IVC 67 42 4 ABDC
Exhaust Valve Opens - EVO 74.5 50 10.5 BBDC
Exhaust Valve Closes - EVC 24.5 0 -39.5 ATDC (- indicates BTDC)
Exhaust Centerline - ECL 115 115 115
Overlap 57.5 8 -69.5 degrees
DCR = 7.96:1
At a 110LSA +4, this is what you get:
Camshaft Valve Events: 0.006 0.05 0.2
Intake Duration - ID 280 230 154
Exhaust Duration - ED 279 230 151
Lobe Center Angle - LSA 110 110 110
Intake Centerline - ICL 106 106 106
Intake Valve opens - IVO 34 9 -29 BTDC (- indicates ATDC)
Intake Valve closes - IVC 66 41 3 ABDC
Exhaust Valve Opens - EVO 73.5 49 9.5 BBDC
Exhaust Valve Closes - EVC 25.5 1 -38.5 ATDC (- indicates BTDC)
Exhaust Centerline - ECL 114 114 114
Overlap 59.5 10 -67.5 degrees
DCR = 8.02:1
When you specified your preferred street manners, you asked for a cam with a light chop, not a heavy lope. Here's what you got:
Camshaft Valve Events: 0.006 0.05 0.2
Intake Duration - ID 280 230 154
Exhaust Duration - ED 279 230 151
Lobe Center Angle - LSA 112 112 112
Intake Centerline - ICL 108 108 108
Intake Valve opens - IVO 32 7 -31 BTDC (- indicates ATDC)
Intake Valve closes - IVC 68 43 5 ABDC
Exhaust Valve Opens - EVO 75.5 51 11.5 BBDC
Exhaust Valve Closes - EVC 23.5 -1 -40.5 ATDC (- indicates BTDC)
Exhaust Centerline - ECL 116 116 116
Overlap 55.5 6 -71.5 degrees
DCR = 7.90:1
Change it to a 111LSA +4, this is what you get:
Camshaft Valve Events: 0.006 0.05 0.2
Intake Duration - ID 280 230 154
Exhaust Duration - ED 279 230 151
Lobe Center Angle - LSA 111 111 111
Intake Centerline - ICL 107 107 107
Intake Valve opens - IVO 33 8 -30 BTDC (- indicates ATDC)
Intake Valve closes - IVC 67 42 4 ABDC
Exhaust Valve Opens - EVO 74.5 50 10.5 BBDC
Exhaust Valve Closes - EVC 24.5 0 -39.5 ATDC (- indicates BTDC)
Exhaust Centerline - ECL 115 115 115
Overlap 57.5 8 -69.5 degrees
DCR = 7.96:1
At a 110LSA +4, this is what you get:
Camshaft Valve Events: 0.006 0.05 0.2
Intake Duration - ID 280 230 154
Exhaust Duration - ED 279 230 151
Lobe Center Angle - LSA 110 110 110
Intake Centerline - ICL 106 106 106
Intake Valve opens - IVO 34 9 -29 BTDC (- indicates ATDC)
Intake Valve closes - IVC 66 41 3 ABDC
Exhaust Valve Opens - EVO 73.5 49 9.5 BBDC
Exhaust Valve Closes - EVC 25.5 1 -38.5 ATDC (- indicates BTDC)
Exhaust Centerline - ECL 114 114 114
Overlap 59.5 10 -67.5 degrees
DCR = 8.02:1
__________________
2013 Corvette Grand Sport A6 LME forged 416, Greg Good ported TFS 255 LS3 heads, 222/242 .629"/.604" 121LSA Pat G blower cam, ARH 1 7/8" headers, ESC Novi 1500 Supercharger w/8 rib direct drive conversion, 747rwhp/709rwtq on 93 octane, 801rwhp/735rwtq on race fuel, 10.1 @ 147.25mph 1/4 mile, 174.7mph Half Mile.
2016 Corvette Z51 M7 Magnuson Heartbeat 2300 supercharger, TSP LT headers, Pat G tuned, 667rwhp, 662rwtq, 191mph TX Mile.
2009.5 Pontiac G8 GT 6.0L, A6, AFR 230v2 heads. 506rwhp/442rwtq. 11.413 @ 121.29mph 1/4 mile, 168.7mph TX Mile
2000 Pewter Ram Air Trans Am M6 heads/cam 508 rwhp/445 rwtq SAE, 183.092 TX Mile
2022 Cadillac Escalade 6.2L A10 S&B CAI, Corsa catback.
2023 Corvette 3LT Z51 soon to be modified.
Custom LSX tuning in person or via email press here.
2013 Corvette Grand Sport A6 LME forged 416, Greg Good ported TFS 255 LS3 heads, 222/242 .629"/.604" 121LSA Pat G blower cam, ARH 1 7/8" headers, ESC Novi 1500 Supercharger w/8 rib direct drive conversion, 747rwhp/709rwtq on 93 octane, 801rwhp/735rwtq on race fuel, 10.1 @ 147.25mph 1/4 mile, 174.7mph Half Mile.
2016 Corvette Z51 M7 Magnuson Heartbeat 2300 supercharger, TSP LT headers, Pat G tuned, 667rwhp, 662rwtq, 191mph TX Mile.
2009.5 Pontiac G8 GT 6.0L, A6, AFR 230v2 heads. 506rwhp/442rwtq. 11.413 @ 121.29mph 1/4 mile, 168.7mph TX Mile
2000 Pewter Ram Air Trans Am M6 heads/cam 508 rwhp/445 rwtq SAE, 183.092 TX Mile
2022 Cadillac Escalade 6.2L A10 S&B CAI, Corsa catback.
2023 Corvette 3LT Z51 soon to be modified.
Custom LSX tuning in person or via email press here.
